The effect of postnatal caffeine administration on brain myelination

Rat pups were administered caffeine in a dosage of 20 mg/kg, 40 mg/kg or 80 mg/kg daily from birth through 17 days of postnatal age. Pups from each group were sacrificed at 17, 23, 30 or 70 days of age, their brains were removed, and myelin was quantitatively prepared. We observed a dose-dependent lag in brain weight and in myelin concentration through 30 days, with full recovery (and possibly overshoot) of the brain myelin concentration at 70 days. There was a persistent lag in brain weight. No discernible impairment of myelination or weight gain resulted from treatment with 20 mg/kg caffeine. The literature on mildly undernourished rats indicates that undernourishment is not a significant contributing factor.